SINS/GPS Carrier Phase Rate Integrated Navigation System based on Square-root CKF

The integration of Strap-down Inertial Navigation System (SINS) and Global Positioning System(GPS) can not merely reduce the error of navigation system, which would enhance the system dynamic performance. GPS Carrier phase rate is a high-precision measurement without integer ambiguity problem. Moreover, only one GPS receiver is needed for SINS/GPS carrier phase rate integrated navigation system. The measurement of GPS carrier phase rate is derived and a integrated scheme of SINS and GPS carrier phase rate is proposed. Common used nonlinear filter, extended Kalman filter (EKF) has high-order truncation error which affects the system accuracy. An improved cubature Kalman filter (CKF) used square root is introduced. The square-root CKF calculation avoids calculating the Jacobian matrix and has better estimate precision.